Direct reduction of iron (DRI) generates metallic iron in a solid form by removing oxygen from the iron ore by using a reducing gas that can be provided from a synthesis gas. Industrially applied DRI processes include MIDREX, HyL and FINMET, as described in “Development of Reduction Process for the Steel Production” by M. Gojic and S. Kozuh, Kem. Ind. 55 (1) 1-10 (2006).
The reducing gas for the iron ore reduction is typically provided from the synthesis gas obtained from natural gas by catalytic steam methane reforming (SMR). Disadvantages of the catalytic steam reforming process include coking and carbon formation on the catalyst, as well as deactivation of a catalyst in presence of sulphur. To overcome these problems, specific and/or expensive catalysts are used as described in US-A-2005/0058594.
However, it would be advantageous to obtain a DRI process, which is originally designed to be operated with a SMR, and wherein the reducing gas is prepared from a source other than natural gas. Such a process would be advantageous because the use of SMR and the disadvantages thereof are avoided.
EP-A-0916739 describes a process wherein the reducing gas for a DRI process is obtained by gasification of a coal slurry. The reducing gas fed to the DRI includes a recycle gas stream that has exited the DRI, and wherein acid gases have been removed from the recycle gas stream.
It is an object of the present invention to provide a DRI process which can be easily obtained by adapting a DRI process involving a SMR process to prepare the reducing gas.